Locking device for bobbin housings of sewing machines



0a. 29, 1935. w B LTER 2,019,390

LOCKING DEVICE FOR BOBBIN HOUSINGS OF SEWING MACHINES Filed Feb. 25, 1934 Patented Oct. 29, 1935 UNITED STATES PATENT QFFICE LOCKING DEVICE FOR BOBBIN HOUSINGS OF SEWING MACHINES Wilhelm Biilter, Bielefeld, Germany, assignor to Anker Werke Aktiengesellschaft,

Germany Bielefeld,

7 Claims. (Cl. 112-231) This invention relates to a locking device for bobbin housings of sewing machines.

Embodiments of locks for lids or covers of the type disclosed herein are known in which the snapping or fastening parts are completely or partly detachable from the lids. Also constructions are known in which the snapping or fastening parts are in permanent connection with the housing of the mechanism and receive a rocking or shifting movement. This invention relates to a construction of the latter type.

The invention consists particularly in the provision of the snapping and fastening parts joined to a member formed from a single piece, which is preferably rockably mounted upon the bobbin housing forming part of the shuttle mechanism, and. which presses with two spring projections against the cover for the housing in the direction of the axis of the latter. In accordance with the invention, at least one lug is provided on the fastening member, which limits the opening movement thereof by abutting against a bearing-lug cast integral with the housing said bearing lug carrying the fastening member.

By means of the arrangement in accordance with the invention, the advantage is attained that instead of inconvenient fastening and snapping parts for the housing lid, only a single part is necessary, which may be arranged in simple manner for rotatable movement upon the housing. This part is furthermore simple to construct and easy to use. By the attachment of the fastening member upon the housing itself, a shifting of the cover, particularly during the first portion of the locking movement, and the danger of damage attendant the provision of detachable parts, are excluded. The strong spring projections of the holding ring assure a sufficiently fine and uniform tension without the danger of an early fatigue of the parts.

One embodiment of the invention is described hereinafter in conjunction with the accompanying drawing, in which Fig. 1 is a longitudinal sectional view of the device along line I--I of Fig. 2,

Fig. 2 is a left end view of Fig. 1, and

Fig. 3 is a front elevation, with certain parts in section, showing the spring fastening device in open position.

The bobbin housing I, which in known manner is formed as a cast body, has two bearing lugs 2 which extend forwardly of the housing in the direction of its axis. A semi-circular ring forming a fastening member 4 with plane lateral portions 5 is rotatably mounted in these bearing lugs by pins 3. Extensions 6 are bent from the plane portions 5 at right angles thereto and are further bent in such a manner that they terminate in springs 1. Both springs l yieldingly press the housing lid 8 (Fig. 1) inwardly, and they engage 5 in known manner small depressions (not shown) in the lid. The housing cover or lid 8 is provided with two apertures I] and is suitably mounted upon pins 9. The member 4 has a grip projection I2 at its lowest point. A part of each of the 10 plane lateral portions 5 is bent in a direction opposite to the extensions 6 and forms thereby a small locking lug i3, designed to cooperate with the bearing lugs 2.

The device operates in the following manner.

When it is desired to remove the housing cover 8, the member 4 is taken by' its projecting grip l2 and is given a movement in a direction indicated by the arrow I4 shown in Fig. 1. The rocking movement which is thereby imparted to the member 4 is limited by the locking lugs l3 which come to abut against the bearing lugs 2. The open position of the member 4 is shown in Fig. 3, I in which the locking lugs I3 are shown abutting against the bearing lugs 2. tion, the housing lid 8, which in the closed position of the member 4 is uncovered by the ringshaped portion of member 4, is accessible, and it may be lifted off forwardly from its two pins 9.

Having described my invention,

I claim:

1. In a sewing machine, a bobbin housing, a detachable cover at the front end of said housing, and a member rotatably mounted on said housing having integral yielding projections pressing said cover onto said housing.

2. In a sewing machine, a bobbin housing, a detachable cover for said housing at the front side thereof, and a semi-circular member rotatably mounted on said housing having a pair of integral yielding projections pressing against said cover in the direction of the longitudinal axis of said housing.

3. In a sewing machine, a bobbin housing, a detachable cover for said housing at the front side thereof, bearing lugs cast integrally with said housing and projecting at its front side, and a member pivotally mounted in said bearing lugs about an axis perpendicular to the longitudinal axis of said housing, said member having integral yielding projections pressing said cover onto said housing.

4. In a sewing machine, a bobbin housing, a detachable cover for said housing at the front side thereof, bearing lugs cast integrally with In this open posi- 25 said housing and projecting at its front side, and a member pivotally mounted in said bearing lugs about an axis perpendicular to the longitudinal axis of said housing, said member having integral yielding projections pressing said cover onto said housing, and at least one additional integral projection for limiting the pivotal movement of said member upon the disengagement of said yielding projections from said cover.

5. In a sewing machine, a bobbin housing, a detachable cover for said housing at the front side thereof, bearing lugs cast integrally with said housing and projecting at its front side, and a member pivotally mounted in said bearing lugs about an axis perpendicular to the longitudinal axis of said housing, said member having integral yielding projections pressing said cover onto said housing, and additional integral projections for abutting against said bearing lugs in the disengaged position of said member for limiting the pivotal movement thereof.

6. In a sewing machine, a bobbin housing, a

detachable cover for said housing at the front side thereof, bearing lugs cast integrally with said housing and projecting at its front side, and a member pivotally mounted in said bearing lugs about an axis perpendicular to the longitudinal axis of said housing, said member having plane lateral portions bent into yielding projections for pressing said cover onto said housing.

7. In a sewing machine, a bobbin housing, a detachable cover for said housing at the front side thereof, bearing lugs cast integrally with said housing and projecting at its front side, and a member pivotally mounted in said bearing lugs about an axis perpendicular to the longitudinal axis of said housing, said member having plane lateral portions bent into yielding projections for pressing said cover onto said housing, and at least one additional lug bent from said lateral portions for abutting against a bearing lug in the disengaged position of said member for limiting the pivotal movement thereof.

WILHELM BGLTER. 

